Hi Shaofeng,
For your questions: 1) When the Parquet storage is released (say in Kylin 4.0), will the HBase storage still be kept (co-exist), or totally be replaced? I think we will keep an active branch with releases for Hbase storage, it won’t be totally replaced in the near feature. 2) Is there a migration tool for migrating HBase cubes to the new storage? The tool is in the developing plan. What’s more, the metadata will be compatible. Best regards, Ni Chunen / George On 2020/1/21, 4:10 AM, "ShaoFeng Shi" <shaofeng...@apache.org> wrote: Chun en, Thanks for the info. I think we need to discuss more in the community, for example: 1) When the Parquet storage is released (say in Kylin 4.0), will the HBase storage still be kept (co-exist), or totally be replaced? 2) Is there a migration tool for migrating HBase cubes to the new storage? Best regards, Shaofeng Shi 史少锋 Apache Kylin PMC Email: shaofeng...@apache.org Apache Kylin FAQ: https://kylin.apache.org/docs/gettingstarted/faq.html Join Kylin user mail group: user-subscr...@kylin.apache.org Join Kylin dev mail group: dev-subscr...@kylin.apache.org nichunen <n...@apache.org> 于2020年1月20日周一 下午9:38写道： Hi Shaofeng, Below is our plan for this project, any suggestion will be very welcome. 1. In mid-February of 2020, open source the prototype code of this feature to branch "kylin-on-parquet-v2", cube can be bulit with new building engine, and stored with parquet format. 2. In late April of 2020, the query module for the new storage type is scheduled to be ready, a happy path for cube creation, building and query will be available then. 3. In May or June of 2020, a Beta version (Kylin 4.0?) will be released. Best regards, Ni Chunen / George On 01/20/2020 16:00，ShaoFeng Shi<shaofeng...@apache.org> wrote： Hi, Chun en, Thanks for the information. What's the detailed release plan of this feature to the community? Best regards, Shaofeng Shi 史少锋 Apache Kylin PMC Email: shaofeng...@apache.org Apache Kylin FAQ: https://kylin.apache.org/docs/gettingstarted/faq.html Join Kylin user mail group: user-subscr...@kylin.apache.org Join Kylin dev mail group: dev-subscr...@kylin.apache.org Xiaoxiang Yu <x...@apache.org> 于2020年1月20日周一 下午1:59写道： Great news! I can foresee Kylin could be in a more Cloud-Native way after the mature of parquet storage. And I wish the developer team will share more detail for its desgin. -- Best wishes to you ! From ：Xiaoxiang Yu At 2020-01-19 22:22:30, "George Ni" <n...@apache.org> wrote: Hi Kylin users & developers, By-layer Spark Cubing has been introduced into Apache Kylin since v2.0 to achieve better performance and it does run much faster compared to MR engine. Also Hbase has been Kylin’s trustful storage engine since Kylin was born and it has been proved to be a success for providing the ability to handle high concurrency queries in extremely large data scale with low latency. But there are also limitations for HBase, such as filtering is not flexible as we could only filter by RowKey, measures are usually combined together which causes more data to be scanned than requested. So in order to optimize Kylin in both building strategy and storage engine, development team of Kyligence is introducing a new cube building engine which uses Spark Sql to construct cuboids with a new strategy and stores cube results in Parquet files. The building strategy allows Kylin to build cuboids in a smarter way by choosing and building on the optimal cuboid source. And Parquet, a columnar storage format available to any project in the Hadoop ecosystem, will power the filtering ability with the page-level column index and reduce I/O by saving measures in different columns. Also with Storing cuboid in Parquet instead of Hbase, we can utilize Kylin in Cloud Native way. More information on design and technique details will come soon. Below is the comparison in building duration and size of results between By-layer Spark Cubing and the new cubing strategy. Environment 4-nodes Hadoop cluster YRAN has 400GB RAM and 128 cores in total; CDH 5.1, Apache Kylin 3.0. Spark Spark 2.4.1-kylin-r17 Test Data SSB data Cube: 15 dimensions, 3 measures (SUM) Test Scenarios Build the cube at different source size level: 30 million, 60 million source rows; Compare the build time with Spark (by layer) + Hbase and SparkSql + Parquet. Besides, we attempt to resolve many drawbacks in current query engine, which relies heavily on Apache Calcite, such as the performance bottleneck in aggregating large query results which currently can only be operated by a single worker. By embracing SparkSql, this kind of expensive computing can be done distributedly. Also combined with Parquet format, plenty of filtering optimizations could be applied,which will boost Kylin’s query performance significantly. The features will be open source along with technique details in the near future. - https://issues.apache.org/jira/browse/KYLIN-4188 -- --------------------- Best regards, Ni Chunen / George
